[Web support] Add `splitio_web` folder with basic scaffolding#155

EmilianoSanchez merged 3 commits intoFME-11223-web-support_baselinesplitio/flutter-sdk-plugin:FME-11223-web-support_baselinefrom

FME-11223-web-support-plugin-scaffoldsplitio/flutter-sdk-plugin:FME-11223-web-support-plugin-scaffoldCopy head branch name to clipboard